HEMTT Hook Lift Swap

[matt2491]

We've got a M985 HEMTT that we're trying to swap a complete hook lift assembly from a PLS truck on to. We removed the tank and the front mount appears to be very close (certainly close enough) for the hook lift to bolt up to. The rear mount will need modification. But the big problem we're running into is that the M985 truck's transfer case sticks way up above the frame rails. So the bottom of the hook lift assembly hits it before it is sitting on the mounts. It fouls it by like 4-5". Here's a pic of the transfer case in the M985:



Does anyone know how the PLS trucks avoid this interference? Do they have a different transfer case and/or is it mounted in a different way (maybe lower or forward)?

 

[simp5782]

We've got a M985 HEMTT that we're trying to swap a complete hook lift assembly from a PLS truck on to. We removed the tank and the front mount appears to be very close (certainly close enough) for the hook lift to bolt up to. The rear mount will need modification. But the big problem we're running into is that the M985 truck's transfer case sticks way up above the frame rails. So the bottom of the hook lift assembly hits it before it is sitting on the mounts. It fouls it by like 4-5". Here's a pic of the transfer case in the M985:

View attachment 838779

Does anyone know how the PLS trucks avoid this interference? Do they have a different transfer case and/or is it mounted in a different way (maybe lower or forward)?

Move the transfer case forward. I mentioned this to the owner the other day. Or drop it down.

PLS uses the same transfer case with a auxiliary steering system on it so it's a much bigger unit.

PLS uses a 39inch transmission to transfer case shaft. Spicer #818753-2000 So it's not much different from the 985 length, PLS case below.

Location of transfer on a PLS

 

[matt2491]

Appreciate the info. So the transfer case on the PLS is in fact mounted lower than on the M985 to accommodate the hook lift assembly?

What about on this truck?

You can see the transfer case sticking up in this screenshot:

 

[simp5782]

It looks almost the same height on the LVS for the transfer case as the tanker. Look at the rear pump sticking out of the transfer case on the rear. Looks about even with the frame on both.

I've never been around an LVS, only standard HEMTTs and PLS trucks so I don't have one to look at but I believe those cylinders are on the outside of the transfer case as it is pretty narrow on a frame. This is the HET frame below which is the same width inside as a PLS.

 

[simp5782]

@ev2bfree has a M1074 so maybe he can share some pictures of his PLS with it's transfer case setup and cylinder placement

 

[ev2bfree]

We've got a M985 HEMTT that we're trying to swap a complete hook lift assembly from a PLS truck on to. We removed the tank and the front mount appears to be very close (certainly close enough) for the hook lift to bolt up to. The rear mount will need modification. But the big problem we're running into is that the M985 truck's transfer case sticks way up above the frame rails. So the bottom of the hook lift assembly hits it before it is sitting on the mounts. It fouls it by like 4-5". Here's a pic of the transfer case in the M985:

View attachment 838779

Does anyone know how the PLS trucks avoid this interference? Do they have a different transfer case and/or is it mounted in a different way (maybe lower or forward)?

 

[ev2bfree]

The cylinders are just inside and above the frame rails

 

[Gman021]

The lower driveshaft going from the transfer case to the first steering axle is only about 23”, and we would need to move the case right around that distance to clear the mount.

Lowering was our first idea but the driveshaft angles and distance required for clearance made us second guess that.

Lowering the transfer case and moving it backward might work.

 

[matt2491]

It's killing me to know how they fit everything in the M1120A2 (seen in my last post), as it does appear the transfer case is in the same location as the M985.

Hell, maybe the hook lift assembly is different?!

Does anyone here own or have access to a M1120A2?

 

[Gunzy]

It's killing me to know how they fit everything in the M1120A2 (seen in my last post), as it does appear the transfer case is in the same location as the M985.

Hell, maybe the hook lift assembly is different?!

Does anyone here own or have access to a M1120A2?

You may check with a local NG or Reserve unit and ask if you can inspect one of theirs. Of course they will be operating A4s so the T-case position may be different due to the Cat engine and 7 spd Allison in them.

 

[Gman021]

You may check with a local NG or Reserve unit and ask if you can inspect one of theirs. Of course they will be operating A4s so the T-case position may be different due to the Cat engine and 7 spd Allison in them.

We do have one close by.


I had a father & son fabricator team come by and look at the truck. We have the hook lift secured to the rear of the HEMTT right now as we try to figure this out.

He thinks moving the transfer case down will mess up the driveshaft angles. He says there is almost no wiggle room on the angles, maybe a few degrees. His number one option is to do what it takes to make the hook lift clear the transfer case. Possibly moving the mounts a bit forward or back, but I prefer to leave them in the stock position. Most likely putting a spacer in between the mounts to make it clear.

The hook lift might sit a bit higher than stock but a 2" lift might be enough to clear the case. It appears the hook, when picking up a rack, as enough wiggle room to go lower and grab a rack, which makes sense since terrain is not always flat.

I like @simp5782 idea of moving the transfer caseforward, but that lower driveshaft isn't long enough. Unless having an ultra short driveshaft is ok.